1. The Field of the Invention
The present invention relates to an electrical connector and in particular to a shunt protected power connector which will assure shunting of the terminals in one mating half upon disconnect with those terminals remaining shunted until they are at least partially engaged with the other half upon remating of the connector.
2. The Prior Art
There are many instances when it is desirable or essential to shunt terminals of unmated electrical connectors in order to both protect associated circuitry and personnel handling the equipment. For example, in power distribution control equipment it is essential to short out the secondary of a current transformer when a control module is removed. If this is not done, then there is substantial probability of the current transformer burning up and/or exploding in a condition of no load on the secondary.
Another example is in high voltage situations in which connectors intermate with terminals secured to the ends of cables and/or other portions of equipment. The connector usually carries plural conductors which apply high voltage to a load or a current source and comprise the return path from the load or the current source. When the connectors are disconnected, the load or current source may have some residual voltage, even though the supply voltage has been disconnected. The contacts of an unmated connector block are exposed and thereby provide a danger of electrical shock from the residual voltage. One way to minimize the danger of electrical shock is to recess the exposed electrical contacts as far as possible within the confines of the connector block. The contacts, although recessed, are yet exposed and freely accessible through the connector block cavities. Thus, there remains the possibility of shock occurring from accidental contact engagement with the contacts.
The prior art has used many approaches in an attempt to overcome the above mentioned difficulties. For example, U.S. Pat. No. 4,034,172 shows a high voltage connector in which the contacts are deeply recessed within the connector and a crow bar assembly is included. The crow bar assembly serves to short the terminals of the connector upon unmating of the connector members.
U.S. Pat. No. 3,275,765 shows an electrical connector which includes a switching means whereby the terminals are shorted one to another upon unmating of the connector members. U.S. Pat. No. 3,387,104 shows a third approach to the problem in which an actual switching member is included in one connector half. The switch is held in an open position by the mated connector but is allowed to close and short the terminals of the connector upon unmating of the connector members.